From patchwork Wed May 7 10:56:33 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liu Bo X-Patchwork-Id: 4127071 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 2D120BFF02 for ; Wed, 7 May 2014 10:57:12 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 6F00C20253 for ; Wed, 7 May 2014 10:57:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6561E2015D for ; Wed, 7 May 2014 10:57:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932428AbaEGK5D (ORCPT ); Wed, 7 May 2014 06:57:03 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:29970 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932413AbaEGK5A (ORCPT ); Wed, 7 May 2014 06:57:00 -0400 Received: from ucsinet22.oracle.com (ucsinet22.oracle.com [156.151.31.94]) by userp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id s47Auxaq026948 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 7 May 2014 10:57:00 GMT Received: from userz7022.oracle.com (userz7022.oracle.com [156.151.31.86]) by ucsinet22.oracle.com (8.14.5+Sun/8.14.5) with ESMTP id s47AuxxU027672 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 7 May 2014 10:56:59 GMT Received: from abhmp0001.oracle.com (abhmp0001.oracle.com [141.146.116.7]) by userz7022.oracle.com (8.14.5+Sun/8.14.4) with ESMTP id s47Aumev027233 for ; Wed, 7 May 2014 10:56:58 GMT Received: from localhost.localdomain.com (/10.182.228.124) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 07 May 2014 03:56:48 -0700 From: Liu Bo To: linux-btrfs@vger.kernel.org Subject: [PATCH] Btrfs-progs: add xxhash Date: Wed, 7 May 2014 18:56:33 +0800 Message-Id: <1399460193-1713-5-git-send-email-bo.li.liu@oracle.com> X-Mailer: git-send-email 1.8.1.4 In-Reply-To: <1399460193-1713-1-git-send-email-bo.li.liu@oracle.com> References: <1399460193-1713-1-git-send-email-bo.li.liu@oracle.com> X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: root Signed-off-by: Liu Bo --- Makefile | 4 +- crc32c.h | 4 +- disk-io.c | 2 +- hash.h | 2 +- xxhash.c | 448 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ xxhash.h | 171 +++++++++++++++++++++++ 6 files changed, 626 insertions(+), 5 deletions(-) create mode 100644 xxhash.c create mode 100644 xxhash.h diff --git a/Makefile b/Makefile index 369df6c..1d70bc9 100644 --- a/Makefile +++ b/Makefile @@ -16,10 +16,10 @@ cmds_objects = cmds-subvolume.o cmds-filesystem.o cmds-device.o cmds-scrub.o \ cmds-restore.o cmds-rescue.o chunk-recover.o super-recover.o \ cmds-property.o cmds-dedup.o libbtrfs_objects = send-stream.o send-utils.o rbtree.o btrfs-list.o crc32c.o \ - uuid-tree.o + uuid-tree.o xxhash.o libbtrfs_headers = send-stream.h send-utils.h send.h rbtree.h btrfs-list.h \ crc32c.h list.h kerncompat.h radix-tree.h extent-cache.h \ - extent_io.h ioctl.h ctree.h btrfsck.h + extent_io.h ioctl.h ctree.h btrfsck.h xxhash.h TESTS = fsck-tests.sh INSTALL = install diff --git a/crc32c.h b/crc32c.h index c552ef6..6dd0ce2 100644 --- a/crc32c.h +++ b/crc32c.h @@ -25,9 +25,11 @@ #include #endif /* BTRFS_FLAT_INCLUDES */ +#include "xxhash.h" + u32 crc32c_le(u32 seed, unsigned char const *data, size_t length); void crc32c_optimization_init(void); -#define crc32c(seed, data, length) crc32c_le(seed, (unsigned char const *)data, length) +#define crc32c(seed, data, length) XXH32(data, length, 0) #define btrfs_crc32c crc32c #endif diff --git a/disk-io.c b/disk-io.c index 19b95a7..2c72f7f 100644 --- a/disk-io.c +++ b/disk-io.c @@ -67,7 +67,7 @@ u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len) void btrfs_csum_final(u32 crc, char *result) { - *(__le32 *)result = ~cpu_to_le32(crc); + *(__le32 *)result = cpu_to_le32(crc); } static int __csum_tree_block_size(struct extent_buffer *buf, u16 csum_size, diff --git a/hash.h b/hash.h index c0b88a1..2d1a71d 100644 --- a/hash.h +++ b/hash.h @@ -22,6 +22,6 @@ static inline u64 btrfs_name_hash(const char *name, int len) { - return ~(crc32c((u32)(~0), name, len)); + return crc32c((u32)(~0), name, len); } #endif diff --git a/xxhash.c b/xxhash.c new file mode 100644 index 0000000..f855a58 --- /dev/null +++ b/xxhash.c @@ -0,0 +1,448 @@ +/* +xxHash - Fast Hash algorithm +Copyright (C) 2012-2014, Yann Collet. +BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are +met: + +* Redistributions of source code must retain the above copyright +notice, this list of conditions and the following disclaimer. +* Redistributions in binary form must reproduce the above +copyright notice, this list of conditions and the following disclaimer +in the documentation and/or other materials provided with the +distribution. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +You can contact the author at : +- xxHash source repository : http://code.google.com/p/xxhash/ +*/ + + +//************************************** +// Tuning parameters +//************************************** +// Unaligned memory access is automatically enabled for "common" CPU, such as x86. +// For others CPU, the compiler will be more cautious, and insert extra code to ensure aligned access is respected. +// If you know your target CPU supports unaligned memory access, you want to force this option manually to improve performance. +// You can also enable this parameter if you know your input data will always be aligned (boundaries of 4, for U32). +#if defined(__ARM_FEATURE_UNALIGNED) || defined(__i386) || defined(_M_IX86) || defined(__x86_64__) || defined(_M_X64) +# define XXH_USE_UNALIGNED_ACCESS 1 +#endif + +// XXH_ACCEPT_NULL_INPUT_POINTER : +// If the input pointer is a null pointer, xxHash default behavior is to trigger a memory access error, since it is a bad pointer. +// When this option is enabled, xxHash output for null input pointers will be the same as a null-length input. +// This option has a very small performance cost (only measurable on small inputs). +// By default, this option is disabled. To enable it, uncomment below define : +//#define XXH_ACCEPT_NULL_INPUT_POINTER 1 + +// XXH_FORCE_NATIVE_FORMAT : +// By default, xxHash library provides endian-independant Hash values, based on little-endian convention. +// Results are therefore identical for little-endian and big-endian CPU. +// This comes at a performance cost for big-endian CPU, since some swapping is required to emulate little-endian format. +// Should endian-independance be of no importance for your application, you may set the #define below to 1. +// It will improve speed for Big-endian CPU. +// This option has no impact on Little_Endian CPU. +#define XXH_FORCE_NATIVE_FORMAT 0 + + +//************************************** +// Compiler Specific Options +//************************************** +#define FORCE_INLINE static inline __attribute__((always_inline)) + + +//************************************** +// Includes & Memory related functions + +#include "xxhash.h" +#include "kerncompat.h" +#include +#include +#include +#include +#include +#include +#include + + + + +//************************************** +// Modify the local functions below should you wish to use some other memory related routines + +FORCE_INLINE void* XXH_malloc(size_t s) +{ + return kmalloc(s, GFP_KERNEL); +} + +FORCE_INLINE void XXH_free(void* p) +{ + kfree(p); +} + +FORCE_INLINE void* XXH_memcpy(void* dest, const void* src, size_t size) +{ + return memcpy(dest, src, size); +} + + +//************************************** +// Basic Types +//************************************** +typedef unsigned char BYTE; +typedef unsigned short U16; +typedef unsigned int U32; +typedef signed int S32; +typedef unsigned long long U64; + +typedef struct _U32_S { + U32 v; +} __attribute__ ((__packed__)) U32_S; + +#define A32(x) (((U32_S *)(x))->v) + + +//*************************************** +// Compiler-specific Functions and Macros +//*************************************** + +// Note : although _rotl exists for minGW (GCC under windows), performance seems poor +#define XXH_rotl32(x,r) ((x << r) | (x >> (32 - r))) + +#define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__) + +#if GCC_VERSION >= 403 + #define XXH_swap32 __builtin_bswap32 +#else + static inline U32 XXH_swap32 (U32 x) + { + return ((x << 24) & 0xff000000 ) | + ((x << 8) & 0x00ff0000 ) | + ((x >> 8) & 0x0000ff00 ) | + ((x >> 24) & 0x000000ff ); + } +#endif + + +//************************************** +// Constants +//************************************** +#define PRIME32_1 2654435761U +#define PRIME32_2 2246822519U +#define PRIME32_3 3266489917U +#define PRIME32_4 668265263U +#define PRIME32_5 374761393U + + +//************************************** +// Architecture Macros +//************************************** +typedef enum { + XXH_bigEndian=0, + XXH_littleEndian=1 +} XXH_endianess; + +#ifndef XXH_CPU_LITTLE_ENDIAN // It is possible to define XXH_CPU_LITTLE_ENDIAN externally, for example using a compiler switch + static const int one = 1; +# define XXH_CPU_LITTLE_ENDIAN (*(char*)(&one)) +#endif + + +//************************************** +// Macros +//************************************** +#define XXH_STATIC_ASSERT(c) { enum { XXH_static_assert = 1/(!!(c)) }; } // use only *after* variable declarations + + +//**************************** +// Memory reads +//**************************** +typedef enum { + XXH_aligned, + XXH_unaligned +} XXH_alignment; + +FORCE_INLINE U32 XXH_readLE32_align(const U32* ptr, XXH_endianess endian, XXH_alignment align) +{ + if (align == XXH_unaligned) + return endian == XXH_littleEndian ? A32(ptr) : XXH_swap32(A32(ptr)); + else + return endian == XXH_littleEndian ? *ptr : XXH_swap32(*ptr); +} + +FORCE_INLINE U32 XXH_readLE32(const U32* ptr, XXH_endianess endian) { + return XXH_readLE32_align(ptr, endian, XXH_unaligned); +} + + +//**************************** +// Simple Hash Functions +//**************************** +FORCE_INLINE U32 XXH32_endian_align(const void* input, int len, U32 seed, XXH_endianess endian, XXH_alignment align) +{ + const BYTE* p = (const BYTE*)input; + const BYTE* const bEnd = p + len; + U32 h32; + +#ifdef XXH_ACCEPT_NULL_INPUT_POINTER + if (p==NULL) { len=0; p=(const BYTE*)(size_t)16; } +#endif + + if (len>=16) { + const BYTE* const limit = bEnd - 16; + U32 v1 = seed + PRIME32_1 + PRIME32_2; + U32 v2 = seed + PRIME32_2; + U32 v3 = seed + 0; + U32 v4 = seed - PRIME32_1; + + do { + v1 += XXH_readLE32_align((const U32*)p, endian, align) * PRIME32_2; v1 = XXH_rotl32(v1, 13); v1 *= PRIME32_1; p+=4; + v2 += XXH_readLE32_align((const U32*)p, endian, align) * PRIME32_2; v2 = XXH_rotl32(v2, 13); v2 *= PRIME32_1; p+=4; + v3 += XXH_readLE32_align((const U32*)p, endian, align) * PRIME32_2; v3 = XXH_rotl32(v3, 13); v3 *= PRIME32_1; p+=4; + v4 += XXH_readLE32_align((const U32*)p, endian, align) * PRIME32_2; v4 = XXH_rotl32(v4, 13); v4 *= PRIME32_1; p+=4; + } while (p<=limit); + + h32 = XXH_rotl32(v1, 1) + XXH_rotl32(v2, 7) + XXH_rotl32(v3, 12) + XXH_rotl32(v4, 18); + } else { + h32 = seed + PRIME32_5; + } + + h32 += (U32)len; + + while (p <= bEnd - 4) { + h32 += XXH_readLE32_align((const U32*)p, endian, align) * PRIME32_3; + h32 = XXH_rotl32(h32, 17) * PRIME32_4 ; + p += 4; + } + + while (p < bEnd) { + h32 += (*p) * PRIME32_5; + h32 = XXH_rotl32(h32, 11) * PRIME32_1 ; + p++; + } + + h32 ^= h32 >> 15; + h32 *= PRIME32_2; + h32 ^= h32 >> 13; + h32 *= PRIME32_3; + h32 ^= h32 >> 16; + + return h32; +} + + +U32 XXH32(const void* input, int len, U32 seed) +{ +#if 0 + // Simple version, good for code maintenance, but unfortunately slow for small inputs + void* state = XXH32_init(seed); + XXH32_update(state, input, len); + return XXH32_digest(state); +#else + + XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN; + + #if !defined(XXH_USE_UNALIGNED_ACCESS) + if ((((size_t)input) & 3)) { // Input is aligned, let's leverage the speed advantage + if ((endian_detected == XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT) + return XXH32_endian_align(input, len, seed, XXH_littleEndian, XXH_aligned); + else + return XXH32_endian_align(input, len, seed, XXH_bigEndian, XXH_aligned); + } + #endif + + if ((endian_detected == XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT) + return XXH32_endian_align(input, len, seed, XXH_littleEndian, XXH_unaligned); + else + return XXH32_endian_align(input, len, seed, XXH_bigEndian, XXH_unaligned); +#endif +} + +//**************************** +// Advanced Hash Functions +//**************************** + +struct XXH_state32_t { + U64 total_len; + U32 seed; + U32 v1; + U32 v2; + U32 v3; + U32 v4; + int memsize; + char memory[16]; +}; + + +int XXH32_sizeofState() +{ + XXH_STATIC_ASSERT(XXH32_SIZEOFSTATE >= sizeof(struct XXH_state32_t)); // A compilation error here means XXH32_SIZEOFSTATE is not large enough + return sizeof(struct XXH_state32_t); +} + + +XXH_errorcode XXH32_resetState(void* state_in, U32 seed) +{ + struct XXH_state32_t * state = (struct XXH_state32_t *) state_in; + state->seed = seed; + state->v1 = seed + PRIME32_1 + PRIME32_2; + state->v2 = seed + PRIME32_2; + state->v3 = seed + 0; + state->v4 = seed - PRIME32_1; + state->total_len = 0; + state->memsize = 0; + return XXH_OK; +} + + +void* XXH32_init (U32 seed) +{ + void* state = XXH_malloc(sizeof(struct XXH_state32_t)); + XXH32_resetState(state, seed); + return state; +} + + +FORCE_INLINE XXH_errorcode XXH32_update_endian (void* state_in, const void* input, int len, XXH_endianess endian) +{ + struct XXH_state32_t * state = (struct XXH_state32_t *) state_in; + const BYTE* p = (const BYTE*)input; + const BYTE* const bEnd = p + len; + +#ifdef XXH_ACCEPT_NULL_INPUT_POINTER + if (input == NULL) + return XXH_ERROR; +#endif + + state->total_len += len; + + if (state->memsize + len < 16) { // fill in tmp buffer + XXH_memcpy(state->memory + state->memsize, input, len); + state->memsize += len; + return XXH_OK; + } + + if (state->memsize) // some data left from previous update + { + XXH_memcpy(state->memory + state->memsize, input, 16-state->memsize); + { + const U32* p32 = (const U32*)state->memory; + state->v1 += XXH_readLE32(p32, endian) * PRIME32_2; state->v1 = XXH_rotl32(state->v1, 13); state->v1 *= PRIME32_1; p32++; + state->v2 += XXH_readLE32(p32, endian) * PRIME32_2; state->v2 = XXH_rotl32(state->v2, 13); state->v2 *= PRIME32_1; p32++; + state->v3 += XXH_readLE32(p32, endian) * PRIME32_2; state->v3 = XXH_rotl32(state->v3, 13); state->v3 *= PRIME32_1; p32++; + state->v4 += XXH_readLE32(p32, endian) * PRIME32_2; state->v4 = XXH_rotl32(state->v4, 13); state->v4 *= PRIME32_1; p32++; + } + p += 16-state->memsize; + state->memsize = 0; + } + + if (p <= bEnd-16) { + const BYTE* const limit = bEnd - 16; + U32 v1 = state->v1; + U32 v2 = state->v2; + U32 v3 = state->v3; + U32 v4 = state->v4; + + do { + v1 += XXH_readLE32((const U32*)p, endian) * PRIME32_2; v1 = XXH_rotl32(v1, 13); v1 *= PRIME32_1; p+=4; + v2 += XXH_readLE32((const U32*)p, endian) * PRIME32_2; v2 = XXH_rotl32(v2, 13); v2 *= PRIME32_1; p+=4; + v3 += XXH_readLE32((const U32*)p, endian) * PRIME32_2; v3 = XXH_rotl32(v3, 13); v3 *= PRIME32_1; p+=4; + v4 += XXH_readLE32((const U32*)p, endian) * PRIME32_2; v4 = XXH_rotl32(v4, 13); v4 *= PRIME32_1; p+=4; + } while (p<=limit); + + state->v1 = v1; + state->v2 = v2; + state->v3 = v3; + state->v4 = v4; + } + + if (p < bEnd) { + XXH_memcpy(state->memory, p, bEnd-p); + state->memsize = (int)(bEnd-p); + } + + return XXH_OK; +} + +XXH_errorcode XXH32_update(void* state_in, const void* input, int len) +{ + XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN; + + if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT) + return XXH32_update_endian(state_in, input, len, XXH_littleEndian); + else + return XXH32_update_endian(state_in, input, len, XXH_bigEndian); +} + + + +FORCE_INLINE U32 XXH32_intermediateDigest_endian (void* state_in, XXH_endianess endian) +{ + struct XXH_state32_t * state = (struct XXH_state32_t *) state_in; + const BYTE * p = (const BYTE*)state->memory; + BYTE* bEnd = (BYTE*)state->memory + state->memsize; + U32 h32; + + if (state->total_len >= 16) { + h32 = XXH_rotl32(state->v1, 1) + XXH_rotl32(state->v2, 7) + XXH_rotl32(state->v3, 12) + XXH_rotl32(state->v4, 18); + } else { + h32 = state->seed + PRIME32_5; + } + + h32 += (U32)state->total_len; + + while (p <= bEnd - 4) { + h32 += XXH_readLE32((const U32*)p, endian) * PRIME32_3; + h32 = XXH_rotl32(h32, 17) * PRIME32_4; + p+=4; + } + + while (p> 15; + h32 *= PRIME32_2; + h32 ^= h32 >> 13; + h32 *= PRIME32_3; + h32 ^= h32 >> 16; + + return h32; +} + + +U32 XXH32_intermediateDigest (void* state_in) +{ + XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN; + + if ((endian_detected == XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT) + return XXH32_intermediateDigest_endian(state_in, XXH_littleEndian); + else + return XXH32_intermediateDigest_endian(state_in, XXH_bigEndian); +} + + +U32 XXH32_digest (void* state_in) +{ + U32 h32 = XXH32_intermediateDigest(state_in); + + XXH_free(state_in); + + return h32; +} diff --git a/xxhash.h b/xxhash.h new file mode 100644 index 0000000..97a1bb2 --- /dev/null +++ b/xxhash.h @@ -0,0 +1,171 @@ +/* + xxHash - Fast Hash algorithm + Header File + Copyright (C) 2012-2014, Yann Collet. + BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions are + met: + + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above + copyright notice, this list of conditions and the following disclaimer + in the documentation and/or other materials provided with the + distribution. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + + You can contact the author at : + - xxHash source repository : http://code.google.com/p/xxhash/ +*/ + +/* Notice extracted from xxHash homepage : + +xxHash is an extremely fast Hash algorithm, running at RAM speed limits. +It also successfully passes all tests from the SMHasher suite. + +Comparison (single thread, Windows Seven 32 bits, using SMHasher on a Core 2 Duo @3GHz) + +Name Speed Q.Score Author +xxHash 5.4 GB/s 10 +CrapWow 3.2 GB/s 2 Andrew +MumurHash 3a 2.7 GB/s 10 Austin Appleby +SpookyHash 2.0 GB/s 10 Bob Jenkins +SBox 1.4 GB/s 9 Bret Mulvey +Lookup3 1.2 GB/s 9 Bob Jenkins +SuperFastHash 1.2 GB/s 1 Paul Hsieh +CityHash64 1.05 GB/s 10 Pike & Alakuijala +FNV 0.55 GB/s 5 Fowler, Noll, Vo +CRC32 0.43 GB/s 9 +MD5-32 0.33 GB/s 10 Ronald L. Rivest +SHA1-32 0.28 GB/s 10 + +Q.Score is a measure of quality of the hash function. +It depends on successfully passing SMHasher test set. +10 is a perfect score. +*/ + +#pragma once + +#ifndef __XXHASH__ +#define __XXHASH__ + +#if defined (__cplusplus) +extern "C" { +#endif + + +//**************************** +// Type +//**************************** +typedef enum { + XXH_OK=0, + XXH_ERROR +} XXH_errorcode; + + + +//**************************** +// Simple Hash Functions +//**************************** + +/* +XXH32() : + Calculate the 32-bits hash of sequence of length "len" stored at memory address "input". + The memory between input & input+len must be valid (allocated and read-accessible). + "seed" can be used to alter the result predictably. + This function successfully passes all SMHasher tests. + Speed on Core 2 Duo @ 3 GHz (single thread, SMHasher benchmark) : 5.4 GB/s + Note that "len" is type "int", which means it is limited to 2^31-1. + If your data is larger, use the advanced functions below. +*/ +unsigned int XXH32 (const void* input, int len, unsigned int seed); + + + +//**************************** +// Advanced Hash Functions +//**************************** + +void* XXH32_init (unsigned int seed); +XXH_errorcode XXH32_update (void* state, const void* input, int len); +unsigned int XXH32_digest (void* state); + +/* +These functions calculate the xxhash of an input provided in several small packets, +as opposed to an input provided as a single block. + +It must be started with : +void* XXH32_init() +The function returns a pointer which holds the state of calculation. + +This pointer must be provided as "void* state" parameter for XXH32_update(). +XXH32_update() can be called as many times as necessary. +The user must provide a valid (allocated) input. +The function returns an error code, with 0 meaning OK, and any other value meaning there is an error. +Note that "len" is type "int", which means it is limited to 2^31-1. +If your data is larger, it is recommended to chunk your data into blocks +of size for example 2^30 (1GB) to avoid any "int" overflow issue. + +Finally, you can end the calculation anytime, by using XXH32_digest(). +This function returns the final 32-bits hash. +You must provide the same "void* state" parameter created by XXH32_init(). +Memory will be freed by XXH32_digest(). +*/ + + +int XXH32_sizeofState(void); +XXH_errorcode XXH32_resetState(void* state, unsigned int seed); + +#define XXH32_SIZEOFSTATE 48 +typedef struct { long long ll[(XXH32_SIZEOFSTATE+(sizeof(long long)-1))/sizeof(long long)]; } XXH32_stateSpace_t; +/* +These functions allow user application to make its own allocation for state. + +XXH32_sizeofState() is used to know how much space must be allocated for the xxHash 32-bits state. +Note that the state must be aligned to access 'long long' fields. Memory must be allocated and referenced by a pointer. +This pointer must then be provided as 'state' into XXH32_resetState(), which initializes the state. + +For static allocation purposes (such as allocation on stack, or freestanding systems without malloc()), +use the structure XXH32_stateSpace_t, which will ensure that memory space is large enough and correctly aligned to access 'long long' fields. +*/ + + +unsigned int XXH32_intermediateDigest (void* state); +/* +This function does the same as XXH32_digest(), generating a 32-bit hash, +but preserve memory context. +This way, it becomes possible to generate intermediate hashes, and then continue feeding data with XXH32_update(). +To free memory context, use XXH32_digest(), or free(). +*/ + + + +//**************************** +// Deprecated function names +//**************************** +// The following translations are provided to ease code transition +// You are encouraged to no longer this function names +#define XXH32_feed XXH32_update +#define XXH32_result XXH32_digest +#define XXH32_getIntermediateResult XXH32_intermediateDigest + + + +#if defined (__cplusplus) +} +#endif + +#endif